Access to Far Northern Cities

Server sky arrays in equatorial orbits will not be visible to cities in the far south and north. An m288 orbit at 12789km radius will be just at the horizon at latitudes of 60.1 degrees north and south.

This is not a problem for cities in the southern hemisphere, such as Santiago at 33 degrees south, Capetown at 34 degrees south, or Christchurch at 44 degrees south. The farthest south town likely to use server sky might be Stanley in the Falklands, at 52 degrees south.

There are many more cities farther north. The largest city in the far north is Murmansk at 69N. Fairbanks is at 65N, Reykjavik is at 64N. Stockholm, Oslo, Helsinki, and Saint Petersburg are all around 60N. For these far northern cities, all of the server sky orbit will be below the horizon. Moscow is at 56N, and Edmonton is at 54N. A small portion of server sky may be visible from the tops of south facing hills.

These northern cities can be reached by satellite relay and terrestrial optical fiber.

The Iridium satellites orbit at 780 kilometers altitude, with an inclination of 86 degrees. They are visible from the poles, and are always (barely) visible from part of the server sky constellation. At the northernmost part of their orbit, they are 4 degrees from the pole, and the radio path to server sky orbits skims only 50km above the Earth's surface. Polar regions will relay through more than one Iridium satellite - which the Iridium system is designed to do. One or two hop relays should be able to reach the entire populated earth.

Globalstar satellites orbit at 1400 kilometers altitude, with an inclination of 52 degrees. They are not visible from the poles, but they are visible from all northern cities, and always visible at high altitude from the server sky orbits.

These satellites may not be directly usable by any server sky satellite, since they operate on lower frequency bands than are planned for server sky. However, some versions of server sky satellites may have additional radios, and can be used as high altitude crosslinks for the Iridium and Globalstar constellations. Server sky can use these comsats to deliver internet and computation to remote northern sites. With proper design and radio licensing, old and new systems can operate together synergistically, increasing the capability and economic value of both networks.